The present invention relates to paint removal and, more particularly, to the stripping of paint and other finishes from automobiles prior to re-painting.
It is well-known to those in the automobile body repair and refinishing art that removal of the old automotive finish is the most difficult, time-consuming, and messiest part of the work. Automotive finishes can be removed by sanding and/or with the aid of chemical strippers. When using a chemical stripper, typically a liquid, or more usually, a semi-liquid thin paste, containing the active paint stripper is applied to the auto body to be stripped and allowed to stand until the paint has been lifted from the surface. This may require several hours or even standing overnight. When the paint is at its loosest, it is removed by scraping. This produces a messy deposit on the floor of the work place consisting of strips or scraps of paint film swollen with the still wet paint remover. Inasmuch as the active paint removing agents in the paint remover are irritating to the skin and eyes, protective gloves and goggles are preferably worn for this work. In any event, it is a difficult and unpleasant task to clean up and dispose of the wet paint strippings.
Another disadvantage of commercially available paint removers, particularly for automotive use, is that they have varying degrees of effectiveness, removing most of the paint in some cases, but only part of the paint or hardly any of it in others. Previously available paint removers are particularly ineffective on epoxy, urethane and lacquer finishes, and some automotive undercoats.
Still another disadvantage of currently available chemical paint strippers is that the paint tends to re-adhere to the stripped surface if the paint remover is allowed to stand too long. Therefore, the scraping operation must be conducted at the optimum time to avoid the need to re-apply paint remover with consequent loss of time. This presents a scheduling problem and necessarily reduces efficiency.
The deficiencies of presently available chemical paint removers are so great that some auto body shops resort to the more time-consuming and therefore, expensive sand-blasting and grinding techniques. These methods of paint removal also have the disadvantage of creating a dust problem, requiring the workers to wear protective masks and clothing. Also, as with any operation that creates a dust-laden atmosphere, there is always the possibility of a dust explosion.
In view of the very large volume of automotive refinishing work, and the obvious disadvantages of the current methods of paint removal, it is apparent that there is a pressing need in the art for an improved method of paint removal and improved chemical compositions for this purpose.
It is a primary object of the present invention, therefore, to provide an improved method for removing paint, and particularly automotive paint, and improved chemical compositions for this purpose, which are not subject to the disadvantages of the prior art.
It is another object of the invention to provide an improved method and compositions for paint removal, which reduce labor, increase efficiency, do not require protective clothing during the stripping operation, and which permit easy clean up of the stripped paint.
It is still another object of the invention to provide a method and compositions for paint removal, which prevent re-adhesion of stripped paint to the treated surface.
It is yet another object of the invention to provide a method and compositions for paint removal; which are not only more efficient and convenient than those of the prior art, but which are also less expensive.
It is still another object of the invention to provide a method and compositions capable of completely removing all commercial automotive finishes, including acrylics, synthetics, epoxies, urethanes, lacquers and undercoatings, down to the bare metal with minimal effort in the stripping operation.
It is another object of the invention to provide a method and compositions for automotive paint removal in which the paint is removed in dry flake form without the need for heavy manual scraping.
It is another object of the invention to provide a method and compositions for the removal of automotive paint in which the stripped paint is converted to a dry, frangible mass, which can be removed from the treated surface by compressed air from an air gun to form a dry flaky material easily swept up for disposal.
It is yet another object of the invention to provide paint removing compositions which have good flow and adhesion, long shelf life, non-flammability, good color and low odor.
It is still another object of the invention to provide such compositions which are capable of removing multiple coats of paint in a single operation.